1. Field of the Invention
The present invention relates to a microwave oven, and more particularly to a microwave oven capable of selectively adjusting a capacity of a cooking chamber which is defined within an integrally formed case of the microwave oven.
2. Description of the Prior Art
Generally, a microwave oven is a device for cooking food by using microwaves. The microwaves are generated by a magnetron, and are radiated into the food to collide the molecules in the food so that frictional heat is generated to cook the food. There are various types of microwave ovens, and one example is shown in FIG. 1.
As shown in FIG. 1, the microwave oven includes a body 10 having a box-shaped case 11, and front and rear panels 12 and 13 which are arranged in front and back of the case 11, respectively. In the case 11, a cooking chamber 30 is formed to receive the food to be cooked, and the cooking chamber 30 is opened/closed by a door 20 which is pivotally mounted on one side of the front panel 12.
Meanwhile, as shown in FIG. 2A, the cooking chamber 30 formed within the case 11 has a rather sufficient capacity due to the existence of a first cavity 31 which is concaved from an upper side of the case 11, and a second cavity 32 which is communicated with the first cavity 31.
Then, when manufacturing the microwave oven having the cooking chamber of a reduced capacity, the case 11 is integrally formed in a manner that the space defined by the first cavity 31 is removed, while the space defined by the second cavity 32 remains. Such is shown in FIG. 2B.
Further, the microwave oven includes a device chamber 40 which is defined at an inner side of the microwave oven. In the device chamber 40, electric components such as a magnetron (not shown) for generating high frequency microwaves, a high voltage transformer 41 for transmitting high voltage to the magnetron, and a high voltage capacitor 42, etc., and other components such as a fan motor 43 for cooling the heat generated from the respective electric components, etc., are installed. The device chamber 40 is enclosed by an outer panel 50.
Further, in front of the device chamber 40, a control panel 60 is formed on the front panel 12, having a plurality of function buttons for inputting user's commands about cooking functions and operation execution, etc.
In the microwave oven constructed as above, the cooking operation begins as the user places the receptacle holding the food to be cooked on a tray in the cooking chamber 30, and manipulates the function buttons on the control panel 60. As the cooking operation begins, the microwaves are generated from the magnetron (not shown) in the device chamber 40, and are radiated into the food through certain processes, to heat/cook the food.
The conventional microwave oven, however, has a shortcoming particularly when manufacturing the case for defining the cooking chamber as follows:
As shown in FIG. 2A, when manufacturing the cooking chamber 30 with sufficiently large capacity, the second cavity 32 is communicated with the first cavity 31 which is concaved from the upper side of the case 11. Meanwhile, when manufacturing the cooking chamber 30 with a reduced capacity, the second cavity 31 is removed, and the case 11 is integrally formed as shown in FIG. 2B.
Accordingly, an additional cost is required for molding the case, and the manufacturing cost increases.